Cord adjusting apparatus for venetian blinds



W. W. LEW IS June 12, 1945.

CORD ADJUSTING APPARATUS FOR-VENETIA'N BLINDS Filed July 3, '1943 w m w w B W mew/s Qwk AfTORNE Y Patented June 12, 1945 UNITED} STATES PATENT OFFICE com) ADJUSTING APPARATUS FOR VENETIAN BLINDS William Weaver Lewis, Port Washington, N. Y. Application uly 3, 1943,.Serial No. 493,405

13 Claims. (01. 160- 175) This invention relates topVenetian blind apparatus embodying a cord operated pulleyfor actuatinga mechanism to tilt the slats of the Venetian blind. More particularly, this invention relates to a device actuated by an operator standing on the floor for so controlling the tilting mechanism as to equalize the two ends of the cord passing over the pulley, with'reference to the operator. ing cord are kept substantially equallyaccessible at all times to the operator without excessive reaching, or the aid of a ladder.

In the type of tilting mechanism for Venetian blinds disclosed in-my patent,'No. 2,108,939, issued February 22, 1938, a .cord' operated pulley actuates the mechanism for tilting the slats of the blind. As a consequence of numerous operations of such tilting mechanism, it has been found that, due to slippage ofthe cord passing over the pulley, successive increments of difference are introduced between the opposite ends of the cord passing over thepulleyh These increments are cumulative so that ultimately a.

condition is reached where one end of the operating cord attains a height which tends to be' means that the use of a ladder is required in order to reach the higher end of the cord. Under all circumstances, such use of a ladder is hazardous. It is more so in the case of women, children and elderly men. Further, this means that a ladder is also required to reach the tilting mechanism for adjusting the position of the cord on the pulley so that both ends of the cord. are rendered equally accessible to the operator at the same distance from the floor. Obviously,

when one end of the operating cord is higher from the fioor than the other end so that one cord end isout of reach offthe operator, the Venetian blind is frequently left in such condition that it is closed when it should be opened, and vice versa. In effect, this tends to limit the utility of the Venetian blind.

The present invention is concerned with a device for equalizing the two ends of a Venetianblind operating cord with reference to the fioor on which an operator stands, in a manner which is consistent with the normal actuation of the mechanism for tilting the slats of the Venetian blind.

The present invention contemplates a device which renders operative the tilting mechanism of a Venetian blind in response to a force of one magnitude or less applied to one end of the op-.

erating cord and which renders ineffective the tilting mechanism in response to a force greater Thus, the two ends of the operat-,

in magnitude than the one magnitude applied tothe one end of theoperating cord, while simultaneously therewith'allowing adjustment of the position of the cord passing over thepulley included in the tilting Jmechanism.

The main objectiof the invention is to enable expeditious adjustment of the position of. the operating cord passing over the pulley of a Venetian-blind tilting mechanism.

Another object is to maintain the; two ends of the operating cord of a Venetian-blind tilting apparatus substantially equally accessible to an operator at all times.

In the Venetian-blind tiltingmechanismdisclosed to my patent, supra, a housing attached to the header bar includesinteriorly thereofa worm and worm gear in mesh, the worm being formed integrally with one endof a shaft whose v opposite end extendsiexteriorly of the housing.

A pulley having an operating cord passing there-. over is mounted on the opposite end of the shaft. In a specific embodiment, the presentinvention comprises a resilient member formedin the configuration of a crossand fixedly secured on the shaftat a point exterior ofthe housing and intermediate the latter, and the pulley. The pul- 'ley is mounted to rotatefreely on the shaft, and

its surface facing the housing is provided with one or more radial grooves spaced along its periphery. The resilient member is formed with one or more radial projectionsspaced along the periphery of the surface facing the pulley.

In the 'operationof the specific embodiment of the invention, the resilient member serves to seat normally its individual radial projections in the individual radial grooves of the-pulley such that both ends of the operating cord are substantially equally accessible to the operator. The rotary movements of the pulley are then transmitted Viathe resilient member to the shaft and thereby to the meshing worm and worm gear for effecting the tilting of the Venetian-blind slats in the familiar manner. This is accomplished by applying a force of at least a certain magnitude to the respective ends of the operating cord.

When slippage causes one end of-the operatingv cord to attain a higher level from the iioorthan the other end thereof, the application of the. certain force to the higher end of the operating cord, or the shorter end of the operating cord with respect to the operator, will actuate the tilting mechanism in a direction opposite, to that to which it was operated in the next previous actuation. During such application of the certain force, the individual radial projections remained seated in the individual radial grooves.

When, however, the certain force is insufi'icient to actuate the tilting mechanism farther, a force in excess of the certain force is then applied to the shorter end of the'cord until the pulley unwith the grooved surface of the pulley, the rotary movements of the pulley are not transmitted to the shaft, or to the meshing worm-and worm gear. Thus, the pulley rotates freelyon the shaft to allow adjustment of the position of the operatin cord passing over the pulley. Such adjustment of the operating cord contemplates substantial tangular projection 34 which is accommodated in the axial opening of the worm gear. Aligned semi-circular grooves 35, 35 formed in opposite side walls of the housing and similar grooves 36, 36 provided on acentral portion of the opposite ends of the inner surface of the cover plate con- -stitute, when the cover plate is fastened to the housing, oppositely disposed and circular bearings for a shaft 31.

Intermediate bearing portions 38 and 39 on the shaft journalled in the bearings hereinbefore described is integrally formed a worm 40 which meshes with the worm gear positioned as preequalization of the two ends of the operating cord above the floor, and thereby substantially equal accessibility of the two ends of the operating cord to-the operator. Such equalization of the operating cord is effected in a manner which is consistent with the normal operation of the mechanism for tilting the Venetian blind so that both the adjustment of the operating cordand the tilting of the Venetian blind are accomplished in kindred operations, but with different magnitudes of force. The invention will be readily understood from the following description taken together with the accompanying drawing in which;

Fig. 1 is an exploded perspective view showin a specific illustration of the invention embodied in the tilting mechanism of a Venetian blind;

Fig. 4 is a side elevational view illustratingthe assembly of the specific illustration of the invention according to Fig. 1;

Fig. 5 is an enlarged elevational view of the encircled portion in Fig. 4;

Fig. 6 is an .elevational perspective view of the assembly of the specific illustration of the in vention according to Fig.1, and

Figs. '7 and 8 are fragmentary elevational perspective views of other illustrations of theinvention that may be embodied in Fig. 1.

Referring to Fig. 1, housing It contains a tilting mechanism II whose structure. will be subsequently pointed out, and supportsone end of a tilt bar l2 including a pluralityof slats. 13, Fig. 2, constituting a Venetian blind substantially as disclosed in my patent, supra? Formed inte ral with the lower end of the housing is a mountin plate 14 which is provided with a plurality of openings l5, I5 to receive screws,not shown, for attaching the housing to a header bar l6, Fig. 2. Mounted in the upper end of the housing is a worm gear I! whose opposite peripheral edges I8 and [9, Fig. 3, have a plurality of gear teeth extending slightly obliquely therebetween. These spaced peripheral edges provide bearings for the rotation of the worm gear in the housing. A rectangular opening 2| extending axially of the worm gear aligns with an opening 22 provided in the upper end of the housing and an opening 23 positioned in the upper end of a cover plate 24 for the housing.

An anchor disposed integrally, with and normally of alower portion of the inner surface of the housing is adapted with an interior thread to receive a screw 3| projecting through aperture 32 located at the lower portion of the cover plate whereby the latter may be removably attached to the housing. An angle plate 33 secured to one end of the tilt bar, Fig. 2,is adapted with a recviously mentioned in the upper portion of the housing. One end of the shaft projects exteriorly of the housing, and has mounted thereon a pulley 4| which carries a cord 42, Figs. 2 and 4, for actuating the pulley and thereby the mechanism for tilting the Venetian blind in a manner that will be hereinafter explained. A washer 13 and nut 44 serve to retain the pulley on the shaft.

In accordance with a specific embodiment of the invention, a resilient .and flexible member 50 is provided with a cross-shaped configuration, and is mounted on the shaft intermediate the worm and the pulley. The individual segments 5| of the member '50 are formed, on the surfaces facing the pulley, with individual projections 52 extending in radial directions. These projections are spaced along the effective periphery of the member 50. The pulley is normally mounted to rotate freely on the shaft. A plurality of spaced radial grooves 53 is formed around the outer side face of the pulley facing the member 50. The effective flexibility and resiliency of the member 50 is such that the individual radial projections on the latter are normally seated in the individual radial grooves on the pulley in a firm manner, Figs. 1, 4, 5, and 6. This enables the flexible member 50 to transmit the rotary movement of the pulley to the shaft, in response to the application of suitable force to the respective ends of the pulley cord for purposes that will be presently explained. This causes the tilting mechanism to dispose the slats of the Venetian blind to the desired extent as pointed out in my patent, supra.

In the operation of the invention of Fig. 1, let it be assumed that numerous operations of the tilting mechanism introduce successive increments of difference of length between the two ends of the operating cord. In effect, this means that one end of-the operating cord tends to rise toward thetop of the Venetian blind while the opposite end of the operating cord tends to drop toward the floor on which the operator stands. as previously pointed out, such effect is dueto the slippage of the cord on the periphery of the pulley. To equalize the two ends of the operating cord with reference to the floor, the operator grasps the shorter end'of the operating cord and applies thereto a certain magnitude of force or less to actuate the tilting mechanism in a direction opposite to that to which it was actuated in the next previous actuation. During this application of the certain force, the projections of the member 50 remainseated in the grooves of the pulley. Hence, no relative movement occurs between the member 50 and the pulley, and the member 59 imparts the rotary movement of the pulley to the shaft and thereby to the, worm and worm gear for actuating the tilting mechanism above mentioned.

When however the certain force is inadequate to actuate thetilting, mechanism farther, the slatsv now being tilted to their maximum extent,

a force in excess of .the certain magnitude is applied to theshorter end of thepulleycord until the projections of the member 50 are'oaused to be unseated from the grooves of the pulley whereupon the pulley only is caused to rotate relative to the member 50. As the member 50 is efiectively slidably engaged with the pulley, the rotary I movement of the pulley is not imparted to the shaft, or to the meshing-worm and worm gear. As the pulley now rotates freely on the shaft relative to the fixed member the shorter end of the pulley cord with reference to the hands of the operator is drawn towards the floor and the longer end of the pulleycord with reference to the hands of the operator is elevated at the same time toward the top 'of the Venetian blind until the distances of the individual ends of the pulley cord are substantially equalized with reference to the hands of the operator, and thereby to the floor on which the operator stands. Thus, the adjustment of the position of the operatin cord on the periphery of'the pulley is accomplished. The foregoing is effective regardless of which end of the operating cord is initially the shorter with reference to the hands of the operator.

' In the modification of Fig. 7, spaced radial projections 60 are formed on the surface of pulley 6i facing the housing,and spaced radial grooves 62 are provided on the effective surface of the member 53 facing the pulley so that'the individual radial projections 60 may be seated in and unseated from the individual radial grooves 52 in the manner and for the purpose hereinbefore explained.

In the modification of Fig. 8, a recess formed in each of the contacting surfaces of pulley 65 and member 65 are so oppositely disposed as to constitute substantially acomposite spherical recess in which a ball-bearing 61 is accommodated. A.plurality of such spherical recesses and associated'ball bearings are spaced along the peripheries of the contacting surfaces of the pulley 65 and'resilient member 66. The relative depths of opposing recesses are arranged such that either the pulley 65' or the resilient memberGB is effectively'displaced from the ball bearings. This allows the pulley B5 to rotate relative to the resilient member 66 whereby adjustment of thezposition of. the cord on the periphery of the pulley B5 is accomplished substantially in the manner and for the purposehereinbefore mentioned.

In connection with the members 50, 63 and 68, it is understood that the illustrated embodiments are merely for the purpose of explaining the invention, and are not necessarily limited thereto. Other examples of the suitable resilient connections are two plates in frictional engagement, one ofwhich is affixed to the pulley and the other of which is secured to the resilient member; and spring controlled members having two surfaces mounted in frictional engagement such that one surface is on the pulley and the other surface is on the resilient member. Accordingly, the resilient connections contemplate any means controllable such that a force of certain magnitude or less applied to the respective ends of the pulley cord serves to actuate thetilting mechanism and such that a force in excess of the certain magnitude applied to the respective ends of the pulley cord serves to render the tilting mechanism ineffective while at the same time permitting the pulley to rotate freely on the shaft for the purpose of adjusting the position of the cord along the periphery ofthe pulley.

Although the member 50, Fig. l, is shown with tion, it is not necessarily limited thereto, and may comprise less than four ormore than four-individual segments 5|, including a circular configuration. Also it is apparent that memberifl may be mounted on the shaft 31 at a point which is on the'opposite side of the pulley 4| with reference to the housing l0, Fig. 1. In this case, the con'tacting'surfaceof the member 50 and pulley are arranged to'cooperate in the manner thereinbefore described.

With the foregoing as illustrative examples, still other modifications will occur. to those skilled in the 'art within the scope of the invention evidenced by the appended claims.

What is claimed is: v

1. A Venetian blind driving elementcomprising a positively driven pulley, and at least one resilient element having a'portion mounted ooaxially with said pulley and a further portion en gaging a portion of said pulley, the engaging,

portions of said element and said pulley being formed with substantially wavy surfaces, a raised section of one surface being accommodated in a depressed section of the other surface, both said sections coacting under control of said element for transmitting rotation between said pulley and said element.

2. A Venetian blind driving element comprising a positively driven pulley. having one side face formed with atleast one groove, a shaft on which said pulley freely rotates, resilient means fixedly secured to said shaft, said means having a side face engaging said pulley side face, and at least one projection formed on said side face of said-means, said projection being seated in c said groove and coacting therewith under control of said means for imparting rotary movement of said pulley to said shaft. I

3. A Venetian blind driving element comprising a positively driven pulley, at least one pro-' jection formed adjacent the periphery of said adjacent its periphery, said projection being seated in said groove and coacting therewith under control of said means for imparting rotary movement of said pulley to said shaft.

4. A Venetian blind driving element compris ing 'a positively driven pulley, said pulley having'a surface of one preselected configuration formed on a side face thereof, a shaft on which said pulley rotates freely, a resilient member having an inner portion secured fixedly to said shaft for rotation therewith, said memberghav ing an outer face portion of further preselected configuration engaging said pulley side face, said one and further configurations being complemental to each other and coacting under control of said member for transmitting rotary movement from said pulley to said shaft.

5. 'A- Venetian blind driving element comprising a' shaft, a pulley rotatable freely on said shaft, a wavy surface formed on a side-face of said pulley, resilient. means having an inner portion fixedly mounted on said shaft for rotation four'individual'segments 5| in a crossconfiguraltian blind including means for tiltingsaid-blind, anda cord operated pulley for actuating said tilting means, a wavy surface formed on and extent, and thereafter said ,wavy surfaced end of said resilient member being displaced in opposition. to the resiliency of said resilient member bysaid pulley to permit said pulley to rotate relative to said resilient member for adjusting the position of the cord on said pulley.

'7. In combination with apparatus for a Venetian blind comprising means adapted for rotation to tilt said blind, and acord operated pulley for rotating said tilting means, a wavy surface formed on a side face of said pulley, a plurality of resilient members arranged in a spoke-like manner and having their inner ends rigidly secured to said tilting means, means for rotation therewith, a wavy surface formedon a sideface of the free ends of each of said resilient menu-- bers, said Wavy surfaced ends of said resilient members engaging said wavy surfaced face of said pulley with a force causing said pulley. and said resilient members to rotate together and being so operable for imparting rotary movement of said pulley-to said tilting means until saidblind is tilted substantially to. the maximum extent, and thereafter said wavysurfaced ends of said resilient members being displaced in opposition to the resiliency of said resilient members by the wavy surfaced face of said pulley to permit .saidpulley to rotate relative to said resilient members for adjusting the position of the cord onsaid pulley. r q 8. A combination according to claim '7 in which said .yvayy surfaced face of said pulley in cludes a plurality of spaced recesses, said wavy surfaced end of each of said members includes a projection, said,:projections of I said members being held seated in corresponding recesses by the resiliency of said members for imparting rotary movement of said pulley to said tilting means until said blind is tilted substantially to the maximum extent, and thereafter said projections of said members being unseated from said recesses in opposition to the resiliency of said members by said pulley to permit said pulley .to rotate relative to said members for-adjusting the osition of the cord on said pulley. I

9. A combination according to claim '1 in which said wavy surfaced face of said pulley includes a plurality of spaced projections, said wavy surfaced end of each of said members includes a recess, said projections being seated in corresponding recesses of said members b the resiliency of said members for imparting rotary movement of said pulley to said tilting means until said blind is tilted substantially to the maximum extent, and thereafter said projections being unseated from said recesses of said members in opposition to the resiliency of said members by said pulley to permit said pulley to rotate relative to said members foradjustingthe po sition of the cord on said pulley.

- l6. 'In'combination with apparatus for a Venetian blind including means for tilting said blind,

and a cord operated pulley for actuating said tilting means, a side face of said pulley formed with a plurality of portions lying in one plane, a plurality of resilient members disposed in spoke-like fashion in one plane in proximity of said pulley side face, their inner ends being rigidly secured to said tilting means for actuation therewith, a side face of the outer end of each of said resilient members formed with a plurality of portions lying in one plane, said one plane portions of said members engaging said one plane portions of said pulley and held thereto by the resiliency of said resilient members and causing said-pulley and said resilient members to rotate together and being thus operable-for actuating saidtilting means until said blind is tilted substantially to the maximum extent, and thereafter said one plane portions of said resilient members being displaced in opposition to their resiliency by said one plane portions of said pulley to permit said pulley to rotate relative to said resilient members for adjusting the cord on said pulley.

11. In combination with apparatus for a Venetian blind comprising a shaft, means rigidly secured to said shaft for rotation therewith to tilt said blind, and a cord operated pulley freely rotatable on said shaft, meansfor causing said shaft and said pulley to rotate together to impart rotary movement to said tilt means, and for permitting said pulley to rotate relative to said shaft to adjust the position of the cord on said pulley, comprising one side face of said pulley having atleast one groove, a resilient flexible member disposedradially relative to said shaft and having an inner end secured to said shaft for rotation therewith, at least one projection formed on a side .face of the outer end of said member, said projection being held seated in said groove by the resiliency oi. said member for causing said pulley and said shaft to rotate together to impart rotary movement to said tiltmeans until said blind is tilted substantially to the maximum extent, and thereafter, upon the continued rotation of said pulley, said projection being unseated from said groove in opposition to the resiliency of said member by said pulley permitting said pulley to rotate relative to said shaft to adjust the position of the cord on said pulley.

12. A combination according to claim 11 in which said projection'is formed on a side face of said pulley, and said groove is formed in a sideface of the outer end of. said member.

13. In combination with apparatus for a Venetian. blind including means for tilting said blind, and a cord operated pulley for rotating said tilting means, resilient means secured rigidly to said tilting means and engaging a portion of said pulley. and being held yieldingly thereto by the resiliency of said resilient means to cause said pulley and saidresilient means to rotate together to impart rotary movement of said pulley to said tiltingv means until said. blind is tilted to the maximum extent, and thereafter, upon the continued rotation of said pulley, said resilient means slidably engaging said portion'of said pulley in opposition to the resiliency of said resilient means by said pulley to permit said pulley to rotate relative to said. resilient means for adjusting the position of the cord on said pulley.

- WEAVER LEWIS. 

